Discovered in 2023, the Borealis mud volcano in the Barents Sea continuously emits methane-rich fluids. Photo: UiT – The Arctic University of Norway / AKMA3
Discovered in 2023, the Borealis mud volcano in the Barents Sea has unveiled some of its secrets to an international research team. A new study highlights its significance as a habitat for numerous marine organisms.
At a depth of 400 meters, about halfway between northern Norway and Svalbard in the Barents Sea, the Borealis mud volcano lies embedded in a crater with a diameter of 300 meters.
The volcano, discovered by researchers from UiT – The Arctic University of Norway, continuously releases methane-rich fluids and is relatively small, measuring approximately seven meters in diameter and 2.5 meters in height.
This makes the findings of an interdisciplinary study by UiT researchers, conducted in collaboration with REV Ocean and several other institutions and published in Nature Communications on January 27, all the more surprising.
The team investigated the volcano using the remotely operated underwater vehicle ROV Aurora and discovered that its environment is not as inhospitable as it might appear.
Unique ecosystem on mineral crusts
The carbonate crusts, in particular—mineral structures formed over thousands of years—offer a stable substrate for various species, some of which are endangered. They serve as a suitable habitat for bottom-dwelling marine animals such as sea anemones, serpulids (tube-building worms), sponges, and even some rare octocoral colonies.
At the same time, the carbonate crusts offer natural protection against bottom trawling, as fishing vessels steer clear of the volcano to avoid damaging their nets.
But it is not only invertebrates that benefit from this unique habitat. The carbonates also provide shelter and food for numerous fish species, including economically important species like saithe and bottom-dwelling fish such as spotted wolffish, cod, four-bearded rockling and redfish of the genus Sebastes.
“The redfish, for instance, is red listed, and we don’t know the consequences if it would disappear. Borealis is an oasis where different species can thrive and flourish,” says Giuliana Panieri, Professor of Geology at UiT’s Faculty of Earth Sciences and lead author of the study, in a university press release.
“Thus, preserving ecosystems such as the Borealis Mud Volcano is essential for maintaining biodiversity and understanding the interactions between geology, geochemistry and biology in marine environments. We need that understanding, among other things, considering that the Arctic seabed plays an important role in oil and gas extraction activities and the emerging deep-sea mining industry.”
Methane leakage for thousands of years
In addition to the unexpectedly high biodiversity, the researchers made further detailed observations during their expedition aboard the research vessel Kronprins Haakon in May 2024.
One of the most striking discoveries: Temperatures at this depth are normally around 4 °C, but Borealis warms its surroundings up to 11.5 °C.
What is particularly fascinating, however, is that the volcano not only spews mud but also continuously releases methane-rich fluids from small mud cones—a process that has likely been ongoing for thousands of years, as indicated by the extensive carbonate deposits.
“The Borealis Mud Volcano is a unique geological and ecological phenomenon that provides a rare insight into the complex interactions between geological processes and marine ecosystems. It is important to preserve these unique habitats, which play a crucial role in maintaining marine biodiversity,” says Panieri.
Protecting the deep sea
The new findings not only have scientific significance, but also implications for the protection of the deep sea. As part of the United Nations’ 30×30 target, Norway has committed to protecting at least 30 percent of its land and sea areas by 2030. The deep sea areas along the Norwegian continental margin in particular could benefit from such protection measures.
One potential threat to the still largely unexplored deep-sea areas is the growing industrial exploitation of the seabed, particularly through oil and gas extraction and the emergence of deep-sea mining. “The responsible management of marine mineral and biological resources is paramount for sustainable development and environmental stewardship in the Arctic region,” the authors emphasize in their study.
Julia Hager, Polar Journal AG
Link to the study: Panieri, G., Argentino, C., Savini, A. et al. Sanctuary for vulnerable Arctic species at the Borealis Mud Volcano. Nat Commun, 2025 DOI: 10.1038/s41467-024-55712-x
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